The present invention relates to an information processing apparatus for accessing memory spaces including a user memory space and a secure memory space.
In maintaining security of a SD card, for example, the password is decoded into decrypted data by hardware using the encryption data and the encryption key in the SD card. In the future, in order to meet the requirement of a plurality of encryption events, the decryption may be executed by software for the contents service such as PDA (personal digital assistant).
As a technique for preventing external leakage of the decryption software, there is a method in which the areas accessible by the user are differentiated in the privileged mode and the normal mode of OS (operating system). There is also a method to prevent external leakage of the decryption software by a hardware memory protection function such as a memory management unit.
In PDA using an open source OS such as Linux, the software development environment is widely disclosed to the users. As a result, the development of applications is facilitated. On the other hand, the encryption key, the data and the instructions stored in the secure memory space inaccessible in the user mode are may be easily stolen by being transferred to the user memory space or the external space using the privileged mode of OS.
In Japan, the digitization in the broadcasting field is under way since December 2000 when the BS digital broadcasting was started. The problem has since been encountered of the violation of the copyright of the digital contents broadcast. Some broadcast contents providers have come to seek strict copyright protection in providing the contents. In order to promote the digitization of the broadcasting media and the smooth distribution of the digital contents, some action must be taken to protect the right to the broadcast contents.